Abstract

The temporal development of strain relaxation is monitored during and immediately after heteroepitaxy by x-ray diffraction with high resolution in strain and time. ZnSe layers on (001)GaAs with thicknesses just a little above the onset of plastic relaxation reveal inhomogeneous, partial relaxation which continues with a time constant of 50 s immediately after the stop of layer growth. A model of generation, glide, and blocking of dislocations well explains the observation that the degree of relaxation finally reached after growth stop is determined by the density of dislocations rapidly generated prior to it.